/**
 *    Copyright (C) 2020-present MongoDB, Inc.
 *
 *    This program is free software: you can redistribute it and/or modify
 *    it under the terms of the Server Side Public License, version 1,
 *    as published by MongoDB, Inc.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    Server Side Public License for more details.
 *
 *    You should have received a copy of the Server Side Public License
 *    along with this program. If not, see
 *    <http://www.mongodb.com/licensing/server-side-public-license>.
 *
 *    As a special exception, the copyright holders give permission to link the
 *    code of portions of this program with the OpenSSL library under certain
 *    conditions as described in each individual source file and distribute
 *    linked combinations including the program with the OpenSSL library. You
 *    must comply with the Server Side Public License in all respects for
 *    all of the code used other than as permitted herein. If you modify file(s)
 *    with this exception, you may extend this exception to your version of the
 *    file(s), but you are not obligated to do so. If you do not wish to do so,
 *    delete this exception statement from your version. If you delete this
 *    exception statement from all source files in the program, then also delete
 *    it in the license file.
 */

#include "mongo/db/pipeline/window_function/window_function_statement.h"

namespace mongo {

WindowFunctionStatement WindowFunctionStatement::parse(BSONElement elem,
                                                       const boost::optional<SortPattern>& sortBy,
                                                       ExpressionContext* expCtx) {
    // 'elem' is a statement like 'v: {$sum: {...}}', whereas the expression is '$sum: {...}'.
    uassert(ErrorCodes::FailedToParse,
            str::stream() << "The field '" << elem.fieldName() << "' must be an object",
            elem.type() == BSONType::object);
    return WindowFunctionStatement(
        elem.fieldName(),
        window_function::Expression::parse(elem.embeddedObject(), sortBy, expCtx));
}

void WindowFunctionStatement::serialize(MutableDocument& outputFields,
                                        const SerializationOptions& opts) const {
    outputFields[opts.serializeFieldPathFromString(fieldName)] = expr->serialize(opts);
}
}  // namespace mongo
